Mumbai University > Computer Engineering > Sem6 > Mobile Communication and Computing

Marks: 5M

Year: Dec 2015

• Mobile IP has several problems with regards to the duration of handover and the scalability of the registration procedure.

• IP mobility protocols can complement mobile IP by offering fast and consistent handover control in limited geographical areas. One among such is Cellular IP.

• Cellular IP provides local handovers without renewed registration by installing a single cellular IP gateway (CIPGW) for each domain, which acts to the foreign world as a foreign agent (FA).

• Inside this domain, each node collect routing information for accessing MNs based on origin of packets sent by the MNs toward the CIPGW.

• Soft handover is achieved by allowing simultaneous forwarding of packets destined for a mobile node along multiple paths. (Soft handover means that during handover, the connection is transferred slowly. Step by step; whereas in hard handover- the old connection is stopped abruptly and new one is started suddenly).

• Thus because of a soft handover, mobile node moving between adjacent cells will temporarily be able to receive packets from the old as well as new BS (if such a feature is allowed by the lower layers).

• The architecture of Cellular IP is simple, elegant and is self-configuring in most conditions.

• Cellular IP requires changes to the basic mobile IP protocol and is not transparent to existing systems.

• The major advantage of Cellular IP is it manageability.

  • Cellular IP is mostly self-configuring and integration of CIPGW with a firewall would help facilitate better mobility administration.

• It also brings along with it its own disadvantages which include:

  • Transparency: The Mobile Nodes needs to be re-configured as Cellular IP is not transparent to existing systems.

  • Efficiency: By forwarding a packet in multiple paths, we are introducing additional network load.

  • Security: A system in the network can obtain a copy of all packets meant for an MN by sending packets with MN’s source address to CIPGW. (Based on 4th point from above.).